Multiple Sclerosis Relapses Don’t Necessarily Occur After Pregnancy

In a new study, researchers say there was no significant increase in relapse rate after childbirth for women with MS.

Pregnancy may not cause multiple sclerosis (MS) to worsen as previously thought.

For the past 20 years, women with MS were told that while pregnancy might help prevent relapses, those relapses often got worse after childbirth.

However, researchers say in a study released today that they discovered the disease didn’t show increased relapse activity after a woman has given birth.

The research team was headed by Dr. Annette Langer-Gould, a clinical assistant professor of neurology at the University of Southern California (USC) Keck School of Medicine as well as an affiliated investigator in neurology with Kaiser Permanente Research.

“This is a super interesting study,” Bruce Bebo, PhD, executive vice president of research at the National Multiple Sclerosis Society, told Healthline.

“We have had this dogma for a long time,” said Bebo. “Women with MS showed an exacerbated rate of relapses after pregnancy, but Dr. Langer-Gould questioned this and found in this preliminary study a different result.”

There are now 15 such treatments approved by the Food and Drug Administration (FDA).

Almost 1 million people in the United States are estimated to be living with MS. Of these, about 70 percent are women.

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The objective of the recent study was to investigate what happens to women with MS after giving birth.

Researchers looked at the risk of relapses and identified potentially modifiable risk factors.

This population study looked at 466 pregnancies from 375 women in the years 2008 to 2016.

The records were taken from the Kaiser Permanente Southern and Northern California databases.

The participants were surveyed about treatments, breastfeeding, and relapses.

“This study provides an important update on previous data, which had indicated that women with MS were more likely to have a relapse in the first three to six months postpartum, with that risk being higher for patients with more active disease before pregnancy,” Dr. Barbara Giesser, professor of clinical neurology at the David Geffen School of Medicine at the University of California Los Angeles (UCLA) and clinical director of the UCLA MS program, told Healthline.

Of the women in the study, 38 percent weren’t on any treatment in the year prior to conception, while 15 percent had clinically isolated syndrome and 8 percent relapsed during pregnancy.

No increase in relapses postpartum were observed, although the authors point out that some of the women had only had a single episode. About one-third of the women breastfed exclusively, which seemed to reduce the relapse rate.

“This is good news for women with MS who wish to have children, and larger population-based studies of this type are encouraged,” noted Giesser.

Immune mechanisms are triggered during pregnancy to keep a woman’s body from rejecting the fetus.

This mechanism is also responsible for suppressing the immune system responsible for MS relapses.

“These results are exciting, as MS is more common among women of childbearing age than in any other group,” Langer-Gould said in a statement.

“This shows us that women with MS today can have children, breastfeed, and resume their treatment without experiencing an increased risk of relapses during the postpartum period,” she added.

“The results are somewhat preliminary and not definitive,” noted Bebo. “But it provides an important piece of information that adds to our knowledge for MS and pregnancy, before and after.”

The authors report the lack of rebound disease activity in the early postpartum period is likely due to a combination of the participants in a population-based setting, inclusion of women diagnosed after a single relapse, and high rates of breastfeeding.

“There were not a lot of people in the study that were on the stronger DMTs, so it may be skewed to a more calm version of disease,” cautioned Bebo, “There wasn’t a lot of exacerbation postpartum.”

“We do not know how certain DMTs will affect pregnancy,” Bebo said.

He emphasized the importance of pregnant women with MS contacting their healthcare provider as soon as possible to us a shared-decision approach to treatment.

“People should have all the information in making family decisions, and this is something that can help,” said Bebo.

“This information is helpful, but everyone needs to evaluate their own circumstance with their healthcare provider to make informed decisions on how to proceed.”